What are the advantages of being able to speak more than on language?

Having a second language not only makes you more marketable, it broadens your horizons in a lot of ways. Your grasp of English improves, vocabulary increases, the ability to communicate is enhanced, cultural understanding and appreciation grow by leaps and bounds and it turns on quiet parts of your brain.

Well big advantage would be that a company would be more likely to hire you. You will be able to communicate better and more efficiently. You could also tell him that you could use it on a vacation to another country.

The ability to speak multiple language allows you to communicate with more people. It makes you eligible for more jobs, and makes you more valuable to employers. It also helps you gain a better understanding of other cultures.